The human response to dietary cholesterol is highly variable. The impact of the variant allele apo A-IV-2 on the response to dietary saturated fat and the mechanisms of the allele are unknown. Dr. Weinberg proposes a matched, controlled dietary trial with lipid measurement, fractional cholesterol absorption and post-prandial triglyceride clearance. Defining the effect of the apo A-IV-2 allele on diet-induced hypercholoesterolemia will further elucidate the impact of genetics on cholesterol metabolism.